Fitting a DRO to my old Colchester Triumph

[Scalarocco]

I had a feeling they might be.
I can't see there is any room at all to provide support underneath. The read head is the full width.
And if setting up these scales was so critical surely they would provide central support on the longer ones?

I've mentioned Heidenhain previously. Some have backing plinths that you set up then clip the scale to it. Others have multiple mounting holes along the top edge. This is an excerpt of a fitting guide I found online as an example. It gives all the GDT stuff, most of which is specific to their product but it gives you an idea of what accuracy they want it mounting to.

 

[skotl]

To be fair to Fizzy, his question mirrored one I had. I used a digital balance, accurate to an alleged 0.1 degree, and it seemed to be good enough. The scales have been on the mill a few years now and haven't missed a beat.
The 1000mm scale also only had a single fitting hole at each end.

 

[Scalarocco]

To be fair to Fizzy, his question mirrored one I had. I used a digital balance, accurate to an alleged 0.1 degree, and it seemed to be good enough. The scales have been on the mill a few years now and haven't missed a beat.
The 1000mm scale also only had a single fitting hole at each end.

Just check the alignment at each end! Any error in the middle is down to the manufacturer. @fizzy what does the book say it should be? Just curious...

 

[fizzy]

Just check the alignment at each end! Any error in the middle is down to the manufacturer. @fizzy what does the book say it should be? Just curious...

Not sure it's chinese
Will check later.

 

[Newlands]

Did you buy it from a U.K. supplier or from Ali/Banggood? I’d quite like one for my lathe but it’s a long bed - probably need something approaching 1500mm and I’m sure that would cost a lot in postage from China (and probably look like a banana when it arrived).

 

[skotl]

Did you buy it from a U.K. supplier or from Ali/Banggood? I’d quite like one for my lathe but it’s a long bed - probably need something approaching 1500mm and I’m sure that would cost a lot in postage from China (and probably look like a banana when it arrived).

Mine came from banggood, was £160 all in for 3 sensors (longest was 1000mm) and the DRO delivered. Took about three weeks, was well packed and came with lots of funky aly mounting brackets and all worked perfectly out of the box.

Edit: My perspective on "well-known" Chinese exporters like AliExpress and Banggood is that it's counter-productive to ship defective products with crummy packaging as one unit that needs to be replaced probably wipes out their profit on ten other sales.
All of that said, I have found that both AE and BG prices have gradually risen over the last few years to the extent that it's often the same price to buy from ArcEurotrade. ebay or amazon. I presume it's all the same widgets so perhaps the exporters are keener to ship a pallet or container to bulk importers rather than 2,000 individual packages to 2,000 individual consumers, so they're starting to dissuade individual buyers

 

[roofman]

Would,nt mind one of these on my radar too for my Harrison...no excuse then for that last cut that goes undersize and wastes 3 hours work

 

[RobCox]

I dont rely on the DRO on my M300 as the last word on how big the workpiece is. Its a Newall Spherosyn setup, was installed before I got the lathe, so not cheapo! Its great for a guide as to roughly where you are, but the last word goes to the micrometer. The DRO cant account for tool pressure, how much will come off in a spring cut, whether when you touched off you gouged a thou into the work etc, so 1um accuracy is wasted (my scales are "only" 5um). For the Z axis though, invaluable.

 

[minimutly]

I dont rely on the DRO on my M300 as the last word on how big the workpiece is. Its a Newall Spherosyn setup, was installed before I got the lathe, so not cheapo! Its great for a guide as to roughly where you are, but the last word goes to the micrometer. The DRO cant account for tool pressure, how much will come off in a spring cut, whether when you touched off you gouged a thou into the work etc, so 1um accuracy is wasted (my scales are "only" 5um). For the Z axis though, invaluable.

Yes yes, all experience...
But the dro gets you there quicker, no?

 

[skotl]

I dont rely on the DRO on my M300 as the last word on how big the workpiece is. Its a Newall Spherosyn setup, was installed before I got the lathe, so not cheapo! Its great for a guide as to roughly where you are, but the last word goes to the micrometer. The DRO cant account for tool pressure, how much will come off in a spring cut, whether when you touched off you gouged a thou into the work etc, so 1um accuracy is wasted (my scales are "only" 5um). For the Z axis though, invaluable.

Nah - my Chinese made DRO, shipped by gawd only knows who and fitted by me, is way more accurate than me and a micrometer.
And faster.

 

[fizzy]

I dont rely on the DRO on my M300 as the last word on how big the workpiece is. Its a Newall Spherosyn setup, was installed before I got the lathe, so not cheapo! Its great for a guide as to roughly where you are, but the last word goes to the micrometer. The DRO cant account for tool pressure, how much will come off in a spring cut, whether when you touched off you gouged a thou into the work etc, so 1um accuracy is wasted (my scales are "only" 5um). For the Z axis though, invaluable.

I only bought the 1um ones as some people reckon the steps convert better when using thou. Going up in 5um steps means rounding up or down gives slightly off results. Accuracy as such wasn't the main reason.
Having said that my old faithful Triumph can easily hit a tenth and on a good day 1 micron over 6". Awesome I love it.

 

[fizzy]

Did you buy it from a U.K. supplier or from Ali/Banggood? I’d quite like one for my lathe but it’s a long bed - probably need something approaching 1500mm and I’m sure that would cost a lot in postage from China (and probably look like a banana when it arrived).

Longer ones are more expensive. Mine came from China and very nicely packed.

 

[fizzy]

Almost finished now. Just got the display to fit and tidying up.
Took me all day today. Thought it would be easy which it was really but I am a perfectionist and things have to be just right. I could never make money at this game!

 

[fizzy]

This is the spacer to fit between the plate and the read head.

 

[Wedg1e]

Needs a rub with some wet'n'dry to give it a 'brushed' look
Of course the forum perfectionists would say it should then be anodised to stop it oxidising with the coolant evaporation...

 

[fizzy]

Needs a rub with some wet'n'dry to give it a 'brushed' look
Of course the forum perfectionists would say it should then be anodised to stop it oxidising with the coolant evaporation...

It's a lot cleaner than it was. Bit of scrap I had lying around. Covered in some sticky goo. Scouring pad and WD40 did the trick.

 

[Wedg1e]

It's a lot cleaner than it was. Bit of scrap I had lying around. Covered in some sticky goo. Scouring pad and WD40 did the trick.

Y'see now I'm looking at DROs on Banggood and Wish... and thinking my '78 Boxford VSL could do with some lovin'

 

[fizzy]

Finished I think.
Used 2 existing holes to mount the DRO arm. Milled an aluminium block to sit inside the box section. Gravity does the rest. Bolt sticks down from the display into a hole free to turn but pretty tight.
Dials match up with motion perfectly.

 

[minimutly]

Finished I think.
Used 2 existing holes to mount the DRO arm. Milled an aluminium block to sit inside the box section. Gravity does the rest. Bolt sticks down from the display into a hole free to turn but pretty tight.
Dials match up with motion perfectly.

View attachment 378736View attachment 378737View attachment 378738View attachment 378739

Does the apron pickup (the long one) need to be the whole length of Tavel? I ask because very little of my work would be beyond the 600mm mark. Can the carriage drive past the end?

 

[fizzy]

Does the apron pickup (the long one) need to be the whole length of Tavel? I ask because very little of my work would be beyond the 600mm mark. Can the carriage drive past the end?

No you can't drive past the end.
But tbh a 1000m scale is still cheap. No real need for the 1200mm one I bought. Price goes up a lot over 1000mm. Doubt I will ever need the full travel.
You could always unbolt the bracket on the rare occasion you need the full travel.